Relational unity based on love is good and necessary of course. I would never discourage that.
Organizational unity to work together is good and necessary also of course. I would never discourage that either.
But neither of these are meant by John 17:21-23. Indeed for a better context of God’s intent the reading should start with verse 17. And then a look at John 16:13; and then a look at John 4:22-24. And other verses of course.
The kind of unity God speaks of is an organic unity in Him first; and then with one another. He speaks of the growth of a spiritual temple in the unity of the faith in which all believers are living stones.
THAT will never translate into a new denomination. And organizationally, the catholic Church (small c) with its thousands of denominations Catholic, Orthodox, and Protestant will NEVER fulfill John 17:21-23.
The cryptic prophetic declaration
about the coming church in Isaiah 48:1 says it all.
Both relational unity and organizational unity - again as necessary as they are for function, or mission as the brother calls it - necessitate the setting aside of doctrinal truth and the non-mention of righteousness.
How could this be the intent of God for believers since we are all called to “walk as He walked.”
There is much, much, much more to understand about preparing the way of the Lord for His soon return than just to be satisfied with a relational unity.
1 Peter 4:17 comes to mind.
Jean-Claude